German patent No. 2,216,982 discloses a support arrangement for a rotary drum wherein running rings are affixed by plates to supporting surfaces of the rotary drum of a rotary kiln. The plates have lateral projections that are affixed to the supporting surface with straps that are attachable to the rotary drum. This arrangement has the disadvantage that, in a cold start condition, the plates must have some clearance between the bore surface of the ring and the supporting surface of the rotary drum to make allowance for the heating and corresponding thermal expansion that occurs during operation. As a result of this clearance, which is undesirable in itself, the covering plates permit fairly large relative movements between the ring and the supporting surface, especially when a cold rotary drum is started up, so that the ring wears comparatively rapidly at its bore surface and must be replaced frequently.
In addition, in the above arrangement, the installation of individual covering plates between the bore surface of the running ring and the supporting surface of the rotary drum is costly and expensive.